docs: Adding a glossary and a prerequirement (#4299)

Signed-off-by: Ana Carolina Costa César <anaipva@gmail.com>
Signed-off-by: Lucas Queiroz <lucas.fn4@gmail.com>
Signed-off-by: Caio Santos <caiobs10@gmail.com>
Signed-off-by: Juan-Ricarte <juanricarte77@gmail.com>
Signed-off-by: Kauan Eiras <kauante@hotmail.com>
Signed-off-by: Miguel de Frias <miguelfrias8@gmail.com>
Signed-off-by: Luiz Pettengill <luizpettengill@hotmail.com>
Signed-off-by: Suzane Duarte <ssuzane9@hotmail.com>
Signed-off-by: Gabriel Ribeiro <gabrielribeirof19@gmail.com>
Signed-off-by: Breno Queiroz Lima <brenob6@gmail.com>
Signed-off-by: Luana Torres <sluana.torres@gmail.com>
Signed-off-by: Jefferson França <jefferson.frds@gmail.com>
Co-authored-by: Gergely Brautigam <182850+Skarlso@users.noreply.github.com>

docs/introduction/getting-started.md

@@ -4,6 +4,8 @@ External-secrets runs within your Kubernetes cluster as a deployment resource.
 It utilizes CustomResourceDefinitions to configure access to secret providers through SecretStore resources
 and manages Kubernetes secret resources with ExternalSecret resources.
 
+This tutorial is intended for those who already have the PreRequisites complete. If there is a term that you don't comprehend, we suggest you to take a look at the Glossary for a general understanding.
+
 > Note: The minimum supported version of Kubernetes is `1.16.0`. Users still running Kubernetes v1.15 or below should upgrade
 > to a supported version before installing external-secrets.
 

hack/api-docs/mkdocs.yml

@@ -52,6 +52,8 @@ nav:
   - Introduction:
       - Introduction: index.md
       - Overview: introduction/overview.md
+      - Glossary: introduction/glossary.md
+      - Prerequisites: introduction/prerequisites.md
       - Getting started: introduction/getting-started.md
       - FAQ: introduction/faq.md
       - Stability and Support: introduction/stability-support.md